Practical 7 Determination of Moisture content by indirect method.ppt
- 1. APE 311 Protected Cultivation and Secondary Agriculture (1+1) Practical - 7 Determination of Moisture content of various grains by indirect method
- 2. Determination of Moisture content by indirect method AIM: To study the moisture content of the given sample by direct method. APPARATUS: Moisture meters, hot air oven, desiccators, balance, grain samples, etc.
- 3. Theory Moisture content The amount of water present in a product and is expressed on the basis of water and usually expressed in %. This per cent moisture content may be expressed on wet basis and dry basis. Let, Ww = wet weight of the sample, g and Wd = dry weight of the sample, g Wm = (Ww – Wd) = moisture weight of the sample, g
- 4. Moisture Content Moisture content …. (1) …. (2) The moisture content expressed at any time on dry basis is proportional to the moisture weight.
- 7. Indirect Method Indirect Method The electrical properties, like, resistance, capacitance and conductance vary with the moisture content. Using the electrical measuring circuit, the moisture content is indirectly measured. Accordingly they are calibrated to measure the moisture content.
- 8. Indirect Method The electronic circuit of a basic moisture meter is given below.
- 9. Indirect Method PSAW Digital Moisture Meter Method PSAW digital moisture meter are designed for quick and accurate determination of moisture content of a wide range of organic and many inorganic materials. The instrument is specially designed for apparently dry granular substances, such as, food grains, seeds, pulses, spices and dehydrated fruits. The operation of PSAW digital moisture meter is based on the fact that the electrical conductivity of a moist material is directly proportional to the amount of moisture contained in it.
- 10. Indirect Method PSAW Digital Moisture Meter Method
- 11. Indirect Method PSAW (Popular science apparatus workshops pvt. Ltd.) Digital Moisture Meter Method Electrical conductivity also varies with the temperature. A built-in temperature sensor along with microprocessor circuitry of the instrument compensate for these variation For uniformity, accuracy and reliability of results the materials under examination is compressed to a particular thickness in order to annul the porosity effect on the electrical conductivity.
- 12. Indirect Method PSAW Digital Moisture Meter Method The rugged mechanical construction of the instrument to withstand high applied pressure coupled with latest electronic technique for reliability and accuracy of results makes it indispensable for grain and seed houses. For a given temperature, the percent moisture content in the material is directly read from correlation dial without making use of any chart or mathematical calculations.
- 13. Indirect Method PSAW Digital Moisture Meter Method PSAW digital moisture meters are, therefore, best suited for quick and accurate determination of percent moisture content in food grains, pulses, oil seeds, vegetable seeds and other granular materials such as, coffee beans, cotton seeds, oats, water melon seeds, etc.
- 14. Indirect Method - PSAW Digital Moisture Meter Method Procedure i. The sample to be tested is taken from a representative sample of the entire lot and thoroughly mixed before testing. ii. A measuring cup of the proper volumes (A, B and C) is filled with the test material up to its brim. The material need not be pressed in the measuring cup rather it should be properly shaken and leveled to avoid superfluous empty spaces in between the grains. The test material is then transferred into the test cup.
- 15. Indirect Method - PSAW Digital Moisture Meter Method Procedure iii. Place the test cup containing the sample in its housing in such a manner that the guide stems of the cup snuggly fits into the hole in the body base. iv. Select the proper compression thickness required for the given test sample from the thickness setting chart. v. Rotate the smaller handle in anti-clockwise direction until the plunger is snuggly compressed against the sample.
- 16. Indirect Method - PSAW Digital Moisture Meter Method Procedure vi. Now fit the Ratchet handle into the open end of bevel pinion and compress the sample until the reading on the main scale and the circular scale divisions together give the correct thickness reading. vii. Press the push type switch on the moisture meter to take the reading after count down from 10 to 1 and temperature correction automatically. The three digits display will give direct moisture percentage after count down.
- 17. Indirect Method - PSAW Digital Moisture Meter Method Procedure viii. To remove the sample, release the pressure between the plunger and the test cup by using ratchet handle in clockwise direction, till movement is free. Remove the rachet handle ix. Use small handle till the pointer goes to the upper most position. Lift the test cup upwards. Remove the test material from the test cup and clean the cup and plunger with a soft piece of cloth. Replace the cup in its position.
- 18. Indirect Method - Universal Moisture Meter Universal Moisture Meter OSAW Universal moisture meter is for quick determination of percent moisture content of a wide range of organic and many inorganic materials. This instrument is mostly suitable for dry granular substances, such as food grains, seeds, pulses, spices, and dehydrated fruits. For a given temperature, the percent moisture content in the material is directly read from the correlator dial without making use of any chart or mathematical calculations.
- 19. Indirect Method - Universal Moisture Meter Scientific Principle: The operation of OSAW Universal moisture meter is based on the fact that the electrical conductivity of a moist material is directly proportional to the amount of moisture contained in it. Electrical conductivity also varies with the temperature.
- 20. Indirect Method - Universal Moisture Meter Scientific Principle: A built- in thermometer and a set of correlator dials on the front panel of the instrument compensates for these variations. For uniformity, accuracy and reliability of results the material under examination is compressed to a particular thickness in order to annul porosity effect on the electrical conductivity.
- 21. Different makes of resistance type moisture meters
- 22. Different makes of capacitance type moisture meters
- 23. Estimation of moisture content of given sample Moisture content of the given samples by indirect method Sample Moisture Content wb, % Moisture Content db, % Groundnut 9.0 9.8 Paddy 10.7 11.9 Sunflower 12.0 13.63
- 24. RESULTS: The moisture content of the given sample by indirect method was found to be: 1. Groundnut i. By wet weight basis in % (w.b.) = ii. By dry weight basis in % (d.b.) = 2. Paddy i. By wet weight basis in % (w.b.) = ii. By dry weight basis in % (d.b.) = 3. Sunflower i. By wet weight basis in % (w.b.) = ii. By dry weight basis in % (d.b.) =